1. Field of the Invention
The present invention relates to an apparatus and method for extracting a salient line for an information sign, and more particularly, to an apparatus and method for extracting salient lines which are cores of information signs (e.g., road markings, traffic signs, guide signs, etc.) to recognize such information signs.
2. Discussion of Related Art
To recognize information signs, such as road markings, traffic signs, guide signs, etc., a region in which each sign exists is detected, and characteristics of each sign are extracted from the detected region. Then, recognition is performed using these pieces of information.
Existing methods for detecting a region of an information sign, such as a traffic sign, are representatively classified into a method using a color and a method using a shape. The method using a color is a technique of detecting a major color of a sign.
As the method using a shape, there is a method of detecting a major shape, for example, a shape surrounded by a circle or a rectangle, of a sign, and so on. In practice, these two methods are frequently used together. Also, techniques, such as edge detection, gradient detection, etc., are used to detect characteristics in a region for recognizing an information sign.
These existing methods of recognizing an information sign involve multistage processing. In particular, a method that is most frequently used for detection is a sliding window technique. The sliding window technique involves repeating a process of searching an overall input image using a particular mask which is changed in size during the processes.
Accordingly, the sliding window technique shows very low computation speed. Consequently, it is difficult to use the sliding window technique in embedded systems, such as a robot, a driverless car, an auxiliary device for safe driving, a guide device for the blind, and so on.